Generic features and parameters of the TML

TML supports the following generic parameters defined in the IlvGraphLayout class (see Base class parameters and features):

Note that all the methods allowing the modification of these parameters are overridden in this subclass. This class keeps track of the changes for parameters that may affect the result of Topological Optimization separately from the parameters that may affect only the nodes placement step. In this way, the Topological Optimization step is not repeated. The previous results are used if no parameters were modified since the last time the layout was successfully performed on the same graph using the same layout instance.

The Topological Optimization step of TML stops if the allowed time setting has elapsed. In the same manner, the Nodes Placement step of TML stops if the allowed time is exceeded. (See Allowed time.)

You can specify separate time settings for each step. Each step is stopped if its specified time limit is exceeded. To learn how to do this, see Optimization iterations and allowed time (TML) and Node placement iterations and allowed time (TML).

In TML, the animation parameter (see Animation) is used only in the Nodes Placement step. If specified, a redraw will be automatically performed after each iteration of the step. This is useful to better understand what is happening during the step and especially if you want to be able to choose the fixed nodes in a manual refinement procedure. (See Using fixed nodes (TML).)

The layout algorithm can use the generic mechanism to lay out connected components. (For more information about this mechanism, see Layout of connected components.)

If the generic connected component layout mechanism is disabled, the algorithm lays out only the connected component that contains the starting node.

If TML produces a layout with overlapping nodes, one possible way to correct the problem is to increase the size of the layout region. (For details, see Using the layout region parameter (TML).)

The layout algorithm can use a link clip interface to clip the end points of a link. (See Link clipping.)

This is useful if the nodes have a nonrectangular shape such as a triangle, rhombus, or circle. If no link clip interface is used, the links are normally connected to the bounding boxes of the nodes, not to the border of the node shapes. See Using a link clipping interface with the TML for details of the link clipping mechanism in TML.

The layout algorithm can use a link connection box interface to calculate the center of a node. See Link connection box. It is used when the option to connect links to node centers or link clipping is enabled. It is only used if the link style is straight line. It is also used for self-links and multilinks, depending on the self-link or multilink mode. See IlvBasicLinkStyleLayout.supportsLinkConnectionBox() for details.

As with all classes supporting this parameter, a certain amount of memory savings can be obtained by selecting this option. Note that using this option does not change the resulting layout. It just slows down the computation. (See Memory savings.)

TML does not reshape the links that are specified as fixed. (See Preserve fixed links. See also Link style (TML).)

TML does not move the nodes that are specified as fixed. Moreover, the algorithm takes into account the fixed nodes when computing the position of the nonfixed nodes. (See Preserve fixed nodes.)

If TML produces a layout with overlapping nodes, you can use the fixed nodes mechanism to correct the problem. (For details, see Using fixed nodes (TML).)

The layout algorithm can save its layout parameters into named properties. This can be used to save layout parameters to .ilv files. (For a detailed description of this feature, see Save parameters to named properties and Saving layout parameters and preferred layouts).

The layout algorithm stops after cleanup if the method IlvTopologicalMeshLayout is called. (For a description of this method in the IlvGraphLayout class, see Stop immediately.) If the layout stops early because the allowed time has elapsed, the result code in the layout report is IlvGraphLayoutReport.STOPPED_AND_INVALID .